Finally, signs of spring are beginning to show here in New England. Birds are singing, and hopefully some of our tiny, shiny little migrants will be returning soon.
There is a Citizen Science project you can participate in that will help document the migration of hummingbirds in the spring:
Starting March 15, 2013, the Audubon Society needs citizen scientists to track, report on, and follow the spring hummingbird migration in real time. A free mobile app makes it easy to report sightings, share photos and learn more about these remarkable birds.
Your participation will help scientists understand how hummingbirds are impacted by climate change, flowering patterns, and feeding by people.
Most people think of hummingbirds as nectar feeders, but they do also snack on insects. Here’s an adorable example:
Many hummer species also steal spiderwebs to make their nests. You can see an Anna’s Hummingbird make her nest with spiderwebs here. Much cuteness and stomping to compact the nesting materials.
I want to highlight this research report for a couple of reasons. First, it’s a summary of a lot of research on birds and bats–and it is alarming. Major findings include:
- Current environmental mercury loads have the ability to significantly reduce reproductive success in several songbird species of conservation concern in the northeastern U.S. including the saltmarsh sparrow and rusty blackbird.
- Bats also build up significant body burdens of mercury; individuals from multiple species from all 10 areas sampled exceeded the subclinical threshold for changes to neurochemistry.
- Mercury loading in songbirds is not only restricted during the breeding season; some species, such as the northern waterthrush, build up high levels of mercury during migration and in tropical wintering areas
From an interview with an author:
“It is a game-changing paradigm shift,’’ Evers said. “For years, we’ve understood the notion that birds like an eagle can obtain toxins by eating a bass, which has eaten a perch, and the perch has eaten a fly. Now we understand the same kind of analogy can be applied to a water thrush, which eats a spider, which has eaten a smaller spider, which has eaten a fly.’’
The other reason I want to point you at this is because it’s a great example of how to produce a report on complex research and make it really accessible. They don’t just have data; they have information on how to interpret the graphs.
The PDF report itself is beautiful to look at, and focuses on specific actions/conclusions that can be drawn from the data. It’s a report that I could hand to any of my non-scientist coworkers and be confident they could read it and understand it. The PDF is presented within the context of a page with lots of supplemental info, including jpgs of some of the figures. This makes it easy for journalists to build a story.
A thermometer is used to indicate risk to certain species–which cleverly uses something commonly associated with Mercury, but also something a lay-person knows how to interpret without a lot of special background knowledge.
Lastly, they cited their research through the report in ways that let you look up the original research, but that doesn’t detract from your reading. It makes a powerful case that we need to really start paying attention to the mercury in our environment–because it’s not just the birds that are exposed.
Most humans–and I include quite a few entomologists in that category–love to hate roaches. This is a sad thing, because the vast majority of roaches never set foot (feet?) in a kitchen. The few species that tap-dance around in your sugar bowl are just a tiny piece of a huge spectrum of amazing roachy biodiversity in the world.
Over 99% of all roach species are innocent soil and forest dwellers, and are important for ecosystem functioning. Some of them can leap like grasshoppers. Some of them can run 4 times faster than a cheetah (well, in terms of body lengths traveled per second, anyway.) The group of insects with the highest frequency of parental care? Roaches. One estimate puts roaches at 24% of all arthropod biomass in tree canopies, and 43% of arthropod biomass in alluvial forests. There are a LOT of roaches in the world, and you’ve never seen or heard of most of them. H. E. Evans may have said it best:
“The study of roaches may lack the aesthetic values of bird-watching and the glamour of space flight, but nonetheless it would seem to be one of the more worthwhile of human activities.” [Life on a Little Known Planet]
This week a new paper came out that highlights the importance of roaches to an animal we have kinder feelings about:
Unusual macrocyclic lactone sex pheromone of Parcoblatta lata, a primary food source of the endangered red-cockaded woodpecker. Eliyahu et. al PNAS Dec. 19 2011
The red-cockaded woodpecker is an adorable little bird that lives in old pine forests. Historically their range covered much of the eastern US, but these days they are down to remnant populations in the southern US, and they’ve been listed as an endangered species since 1970.
Red-cockaded woodpeckers need large stands of old growth long-leaf pine to survive–they are unique because they nest in living trees, not dead trees. And here is where roaches come into the story–69.4% of the food given to nestlings is wood roaches.
Logging has reduced the number of old pines, resulting in a major loss of habitat for the birds. Artificial nesting cavities have been drilled in trees in hopes of getting more birds to breed. Deciding where to drill a nesting cavity means assessing just how many roaches are in an area, and if there are enough roaches around to support a brood of hungry baby birds.
The majority of wood roaches are secretive and nocturnal, so finding them and counting them is not an easy thing. They live underground, under bark, and generally hide in places you can’t see. It’s not only humans that have trouble finding the roaches–this also makes it tough for the roaches to find each other for mating.
Like many other insects, they’ve solved this problem with chemical signals called pheromones. Pheromones are “chemicals emitted by living organisms to send messages to individuals of the same species.” By making a species-specific blend of chemicals and releasing it into the air, insects can communicate over great distances.
With sex pheromones, the message is usually from the female, and has the content “I’m here and ready to get it on, big boy!” Male antennae are exquisitely sensitive to even single molecules of a female sex pheromone. Because of that sensitivity, you can use male antennae as a type of pheromone detector. (Watch an animation of what happens neurologically in an antenna when pheromone hits a receptor, via UC Davis.)
You can hook up a male antenna to electrodes and actually measure just how much the neurons depolarize in response to a specific compound. This is electroantennography, or EAG. In really fancy EAGs, you can run an unknown compound through a gas chromatograph (GC) and an EAG simultaneously. With the help of these expensive machines, you can extract the pheromone gland from a female, get information about the structure of the chemicals from the GC, and figure out just which chemicals are the ones that attract the males with the EAG. The graph at the right is what that looks like.
It’s fairly clear when you find the right molecule–the male antenna produces a big spike like the one you see for compound #1.
(Side note: I actually did a fair amount of EAGs in my earlier research, and I have to say I’ve never felt more like Dr. Frankenstein in my entire life. You basically decapitate an insect and then stick all sorts of electrodes on their brain and antennae, and hook it up to a lot of really, really fancy instrumentation. I kept having to stifle the “Bwa ha ha ha ha ha” that wanted to bubble up, and found myself rubbing my hands together in glee a lot.)
There are many insects for which humans have figured out how to synthesize artificial pheromones and use them as a type of buggy birth control. In this case, knowing what the pheromone is for this wood roach gives humans a simple way to assess how many roaches are in an area under consideration for woodpecker habitat restoration.
You put the pheromone out near a sticky trap; male roaches come a running for some roachy lovin’, and then you count up how many of the unlucky suitors end up dead on a glue trap.
And now a surprise ending much more pleasurable than that experienced by the roaches on this trap: a holiday entomological carol written about this very research!
This carol actually includes some details I left out, like the species name of the roach (Parcoblatta latta); the researcher whose lab this work was done in (Coby Schal); and the use of nuclear-magnetic resonance (NMR) to determine the specific chemical structures. Enjoy!
(to the tune of “Walking in a Winter Wonderland”)
Roaches stink, are you smellin’?
Pheromones, they’re a-tellin’.
So succulent-sweet, what woodpeckers eat.
Parcoblatta lata wonderland.
Dr. Schal took a reading.
Found the compounds for breeding
By using some gas as roaches chased ass.
Parcoblatta lata wonderland.
Nuclear magnetic resonating
Let him know what turned a suitor on.
Then he synthesized a mix for baiting
And watched the males all falling for the con.
Now his sexy solution
Tells about evolution:
Viagra for some, for others it’s dumb.
Parcoblatta lata wonderland.
People say the lata’s a home-wrecker,
But the bugs are happy in the wood,
‘Til they’re chomped by red-cockaded pecker
Who wants a lata latté in the ‘hood.
Synthesized, it’s a winner.
“Go get laid, then be dinner!”
That pheromone blend helps avian friend.
Parcoblatta lata wonderland.
Parcoblatta lata wonderland.
Suggested additional reading:
- Cockroaches: Ecology, behavior, and natural history. 2007. William J. Bell, Louis Marcus Roth, Christine A. Nalepa. Johns Hopkins Press.
- More about the Red-cockaded Woodpecker (USFW)
Eliyahu, D., Nojima, S., Santangelo, R., Carpenter, S., Webster, F., Kiemle, D., Gemeno, C., Leal, W., & Schal, C. (2011). PNAS Plus: Unusual macrocyclic lactone sex pheromone of Parcoblatta lata, a primary food source of the endangered red-cockaded woodpecker Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.1111748109
(this post appeared as a guest post at Scicurious)
Today’s Tuesday Photo is of an adorable little skipper butterfly, courtesy of Shubhada Nikharge. And yes, it is taking a drink from what you think it is–bird poop. Bird droppings have a lot of nitrogen, as well as salts and other minerals that butterflies need. Think of it as a rather splatty vitamin suppliment. Most plants don’t have high salt or nitrogen in their tissues or nectar, so butterflies seek it out from other sources. A little factoid to enjoy with your morning coffee.
A fabulous new development in louse control! I’ve written before about the problem of head lice becoming resistant to commonly used pesticides, making treatment much more difficult. A new device received approval from the FDA to be this year–and it’s a lot of hot air.
Goates, B., Atkin, J., Wilding, K., Birch, K., Cottam, M., Bush, S., & Clayton, D. (2006). An Effective Nonchemical Treatment for Head Lice: A Lot of Hot Air. PEDIATRICS, 118 (5), 1962-1970 DOI: 10.1542/peds.2005-1847
This device is a great story of how basic ecological research can lead to improvements in human health. It all starts with birds.
Those of us who keep chickens or work with wild birds know that they have an amazing assortment of ectoparasites–parasites that live on the outside of the body (“ecto” = external). Most of these are called “feather lice.”
Feather lice are a fascinating group of animals; the researchers in this lab have studied, among other things, how lice have evolved to match the color of their host birds. I think it’s safe to say that Dr. Dale Clayton, the lead researcher in this story, is Mr. Bird Lice. Over the last 2 decades, he’s published a steady stream of fascinating papers (and books!) about lice and their co-evolutionary relationships with their hosts.
It was because of Clayton’s research that the University of Utah lured him away from his job at Oxford in the late 1990s. Unfortunately, Clayton discovered exchanging jolly old (damp) England for Utah’s arid climate made keeping his lousy subjects alive extremely difficult. In fact, his lice colonies dried out and died.
Having dead research subjects will put a serious dent in one’s research productivity.
His travails in lice-rearing, however, were what set a lightbulb off when his children came home with head lice. If his research lice dessicated and died, could he make head lice dry out and die too? Alas, it proved to be a much harder puzzle than he thought:
“Over the next several years a variety of methods were tested in Clayton’s lab, ranging from the use of chemical desiccants, to heat caps fitted with electrodes, to rice bag caps heated in a microwave, to various hair dryers and blowers up to the size of a leaf blower “
After almost 20 years of tinkering, the Lousebuster is now FDA approved and on the market. It also happens does a really, really good job of killing the insects using only hot air!
I know what you are thinking–unfortunately, it is not enough to have a blow-dryer, as you can see here in the results comparing the percent of lice being killed with different methods. (I also am rather relieved that wall-mounted hand driers were not effective. I can only imagine the lines at the airport bathroom if families traveling decided to do a little de–lousing between connections.)
The other nice item is that the company selling the Lousebuster requires that anyone purchasing them be certified in their use. That means that no one should have a scalded scalp, and it should actually perform at the 95-99% louse mortality levels reported in various publications.
A newer version released December 2010 is quieter and “works on curly hair”.
So hoist one to toast Dr. Clayton and his lab in their demonstration of how basic research pays off for all of us!!